Date: Tue, 19 May 2015 14:21:01 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r283109 - head/sys/x86/x86 Message-ID: <201505191421.t4JEL1vd075036@svn.freebsd.org>
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Author: kib Date: Tue May 19 14:21:00 2015 New Revision: 283109 URL: https://svnweb.freebsd.org/changeset/base/283109 Log: When sleeping in Sx state using MWAIT instruction, accept fast wakeup requests from writes to the monitored line. Submitted by: avg Modified: head/sys/x86/x86/cpu_machdep.c Modified: head/sys/x86/x86/cpu_machdep.c ============================================================================== --- head/sys/x86/x86/cpu_machdep.c Tue May 19 14:05:15 2015 (r283108) +++ head/sys/x86/x86/cpu_machdep.c Tue May 19 14:21:00 2015 (r283109) @@ -101,6 +101,10 @@ __FBSDID("$FreeBSD$"); #include <vm/vm_pager.h> #include <vm/vm_param.h> +#define STATE_RUNNING 0x0 +#define STATE_MWAIT 0x1 +#define STATE_SLEEPING 0x2 + /* * Machine dependent boot() routine * @@ -134,13 +138,24 @@ acpi_cpu_idle_mwait(uint32_t mwait_hint) { int *state; - state = (int *)PCPU_PTR(monitorbuf); /* * XXXKIB. Software coordination mode should be supported, * but all Intel CPUs provide hardware coordination. */ + + state = (int *)PCPU_PTR(monitorbuf); + KASSERT(*state == STATE_SLEEPING, + ("cpu_mwait_cx: wrong monitorbuf state")); + *state = STATE_MWAIT; cpu_monitor(state, 0, 0); - cpu_mwait(MWAIT_INTRBREAK, mwait_hint); + if (*state == STATE_MWAIT) + cpu_mwait(MWAIT_INTRBREAK, mwait_hint); + + /* + * We should exit on any event that interrupts mwait, because + * that event might be a wanted interrupt. + */ + *state = STATE_RUNNING; } /* Get current clock frequency for the given cpu id. */ @@ -231,10 +246,6 @@ static int idle_mwait = 1; /* Use MONIT SYSCTL_INT(_machdep, OID_AUTO, idle_mwait, CTLFLAG_RWTUN, &idle_mwait, 0, "Use MONITOR/MWAIT for short idle"); -#define STATE_RUNNING 0x0 -#define STATE_MWAIT 0x1 -#define STATE_SLEEPING 0x2 - #ifndef PC98 static void cpu_idle_acpi(sbintime_t sbt)
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